Cozaar Drug Interactions

Agents Increasing Serum Potassium: Coadministration of losartan with other drugs that raise serum potassium levels may result in hyperkalemia. Monitor serum potassium in such patients.
Lithium: Increases in serum lithium concentrations and lithium toxicity have been reported during concomitant administration of lithium with angiotensin II receptor antagonists. Monitor serum lithium levels during concomitant use.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors): In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including losartan) may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving losartan and NSAID therapy.
The antihypertensive effect of angiotensin II receptor antagonists, including losartan, may be attenuated by NSAIDs, including selective COX-2 inhibitors.
Dual Blockade of the Renin-Angiotensin-Aldosterone System (RAAS): Clinical trial data has shown that dual blockade of the RAAS through the combined use of angiotensin II receptor blockers, ACE inhibitors, or aliskiren is associated with a higher frequency of adverse events such as hypotension, syncope, hyperkalemia, and decreased renal function (including acute renal failure) compared to the use of a single RAAS-acting agent.
The Veterans Affairs Nephropathy in Diabetes (VA NEPHRON-D) trial enrolled 1448 patients with type 2 diabetes, elevated urinary-albumin-to-creatinine ratio, and decreased estimated glomerular filtration rate (GFR 30 to 89.9 mL/min), randomized them to lisinopril or placebo on a background of losartan therapy and followed them for a median of 2.2 years. Patients receiving the combination of losartan and lisinopril did not obtain any additional benefit compared to monotherapy for the combined endpoint of decline in GFR, end stage renal disease, or death, but experienced an increased incidence of hyperkalemia and acute kidney injury compared with the monotherapy group.
In most patients no benefit has been associated with using two RAAS inhibitors concomitantly. In general, avoid combined use of RAAS inhibitors. Closely monitor blood pressure, renal function, and electrolytes in patients on COZAAR and other agents that affect the RAAS.
Do not coadminister aliskiren with COZAAR in patients with diabetes. Avoid use of aliskiren with COZAAR in patients with renal impairment (GFR <60 mL/min).